Bug 894624 - The test suite for new UI components should run only on Australis

- Synchronized `australis` with  `master`
- Added module.metadata to test suite
- Added `assert.throws` when testing property with only getter and not setter

The relevant commit for the [bug 894624](https://bugzilla.mozilla.org/show_bug.cgi?id=894624) is: https://github.com/ZER0/addon-sdk/commit/670a1e4dd551d4fa16ea6e464835630ee8e10b80